Scotland's pro-independence activists received a funding boost of £10,000 from the Proclaimers, it emerged on Tuesday, as the Electoral Commission figures confirmed that the pro-union Better Together campaign has stopped taking donations after reaching its £1.5m funding limit.

A social media campaign is under way to get the singing twins' pro-independence anthem, Cap In Hand, to No 1 in time for the referendum vote, on 18 September.

Better Together appealed for individuals to stop sending money after being flooded with donations following Alastair Darling's strong performance in the first televised debate in early August.

Donations to the official pro-independence campaign for the most recent reporting period from 25 July to 21 August included £50,000 from Elizabeth Topping, the wife of the former William Hill chief executive Ralph Topping, and £75,000 from Randall Foggie, an SNP council candidate from Kirkcaldy.

A Yes Scotland spokesman said: "This is a campaign which has been going for more than two-and-a-half years. As money comes in, a lot of it has been accounted for already and has been spent. We're not in the happy condition that the no campaign has been in where they've pots of it, and don't need more."

Most recent donations on the no side included another £15,000 from the writer Christopher Sansom to the celebrity-backed Let's Stay Together campaign. Sansom has previously donated a total of £200,000 to Better Together.

The Vote No Borders campaign, which has attracted criticism for presenting itself as reflecting Scottish grassroots sentiment when it is run from London, also took donations of £50,000.

Vote No Borders emphasised in its own press release that these came from "three businessmen who are Scottish, state-educated and from working-class backgrounds".

In early June, the first report on campaign donations that covered the longest reporting period from December 2013 to June 2014 revealed that the pro-union campaign had taken more than double the donations received by the campaign for Scottish independence, with significant contributions from Tory backers and senior financiers.